To inflate, put it around your neck and yank down on the tab.
8 seconds sound clip from the Tommy Boy (1995) movie soundboard.
You can hear this line at 01:15:19 in the Blu-ray version of the movie.
Quote context
[...]
- Tommy is a Scorpio, he likes biking, and he's never been laid.
- Exits! Ok, there's one back here, and there's probably one over by the wing, somewhere, usually.
- And what about seat belts? To fasten, take the little end and stick it in the big end.
- To inflate, put it around your neck and yank down on the tab.
- Son of a...! I can't breathe! Chocking!
- He's a big dumb animal, isn't he folks?
- Folks, we're making our final approach into Chicago.
- Ma'am, are you still alive? Ma'am there's a half hour time limit.
[...]